True ileal digestibility of legumes determined by dual isotope tracer method in Indian adults

Kashyap, S., Varkey, A., Shivakumar, N., Devi, S., Reddy, R., Thomas, T., Preston, T. , Sreeman, S. and Kurpad, A. V. (2019) True ileal digestibility of legumes determined by dual isotope tracer method in Indian adults. American Journal of Clinical Nutrition, 110(4), pp. 873-882. (doi: 10.1093/ajcn/nqz159) (PMID:31374575) (PMCID:PMC6766447)

Abstract

Background: Good-quality plant protein sources are important for protein adequacy in a balanced diet. Legumes are known to be a source of good quality plant protein, but the true ileal digestibility of indispensable amino acids (IAAs) of commonly consumed legumes is not known in humans. Objectives: In this study we measured the true ileal IAA digestibility of 2H-intrinsically labeled chickpea, yellow pea, and mung bean (hulled and dehulled) protein, using the dual-isotope tracer technique referenced to a standard protein ([U-13C] spirulina). The study also aimed to validate the use of [U-13C] spirulina as a reference protein in this method. Methods: 2H-intrinsically labeled legumes, obtained by watering plants with deuterium oxide (2H2O), were administered in a plateau feeding method to healthy Indian adults to measure their true ileal IAA digestibility with the dual-isotope tracer technique, using [U-13C] spirulina protein or a 13C-algal IAA mixture as the standard. Result: The true ileal IAA digestibilities (mean ± SD) of chickpea, yellow pea, and mung bean were 74.6 ± 0.8%, 71.6 ± 1.3%, and 63.2 ± 1.5%, respectively. The true mean ileal IAA digestibility of mung bean when referenced to [U-13C] spirulina protein or a 13C-algal IAA mixture did not differ significantly (63.2 ± 1.5% versus 64.0 ± 2.4%, P > 0.05). The true ileal IAA digestibility of mung bean improved to 70.9 ± 2.1% after dehulling. Conclusions: The true mean ileal IAA digestibility of legumes in healthy Indian adults was lower than expected. Traditional processing techniques such as dehulling improve protein digestibility by about 8%. This study was registered in the Clinical Trials Registry of India (CTRI): CTRI/2017/11/010468 (http://ctri.nic.in, accessed on 28/03/2019).

• Item Type: Articles
• Additional Information: This research work was supported by The Wellcome Trust/DBT India Alliance through the Margdarshi fellowship to AVK, and partly by IAEA CRP Code: E4.30.31, Contract no: 19301
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Preston, Professor Tom
• Authors: Kashyap, S., Varkey, A., Shivakumar, N., Devi, S., Reddy, R., Thomas, T., Preston, T., Sreeman, S., and Kurpad, A. V.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: American Journal of Clinical Nutrition
• Publisher: Oxford University Press
• ISSN: 0002-9165
• ISSN (Online): 1938-3207
• Published Online: 02 August 2019
• Copyright Holders: Copyright © 2019 American Society for Nutrition
• First Published: First published in Journal of Nutrition 110(4): 873-882
• Publisher Policy: Reproduced under a Creative Commons License